Antepartum non-invasive evaluation of opening and closing timings of the cardiac valves in fetal cardiac cycle

Abstract

In this study, we propose a non-invasive algorithm to recognize the timings of fetal cardiac events on the basis of analysis of fetal ECG (FECG) and Doppler ultrasound signals. Multiresolution wavelet analysis enabled the frequency contents of the Doppler signals to be linked to the opening (o) and closing (c) of the heart's valves (Aortic (A) and Mitral (M)). M-mode, B-mode and pulsed Doppler ultrasound were used to verify the timings of opening and closure of these valves. In normal fetuses, the time intervals from Q-wave of QRS complex of FECG to opening and closing of aortic valve, i.e., Q-Ao and Q-Ac were found to be 79.3 +/- 17.4 and 224.7 +/- 13.3 ms, respectively. For the mitral valv..